A device and method for reducing the solids content of a slurry in a low temperature chlorination leach system

Abstract

The application is suitable for the technical field of titanium chloride white, and provides a device and method for reducing slurry solid content of a low-temperature chlorination leaching system; the device comprises a chlorination furnace, a low-temperature chlorination leaching tower, a spraying part arranged at a flue gas outlet of the chlorination furnace, a spraying groove for collecting spraying water discharged from the low-temperature chlorination leaching tower, and an organic reagent injection device arranged in the low-temperature chlorination leaching tower; the spraying groove provides spraying water for a heat exchanger through a conveying pump; an output end of the heat exchanger is communicated with an input end of the spraying part through a first conveying pipeline; a solid-liquid separator is further arranged between the heat exchanger and the conveying pump, the solid-liquid separator is used for solid-liquid separation of the spraying water input by the conveying pump, and provides supernatant after solid-liquid separation for the heat exchanger; and the device further comprises a refining system, and a concentrated phase output end of the solid-liquid separator is connected in a slurry evaporation furnace of the refining system.

Description

Technical Field

[0001] This invention relates to the field of titanium dioxide chlorination technology, specifically to an apparatus and method for reducing the solid content of slurry in a low-temperature chlorination leaching system. Background Technology

[0002] Currently, the blast furnace-converter process effectively utilizes iron and vanadium resources in vanadium-titanium magnetite. However, the utilization rate of Ti resources is low, with titanium, accounting for 50% of the total resources, entering the blast furnace slag to form high-titanium blast furnace slag, resulting in a waste of titanium resources. Starting in the 1980s, focusing on the extraction and utilization of titanium resources from high-titanium blast furnace slag, Panzhihua Iron and Steel Group (Pangang) independently developed a technical route for "high-temperature carbonization-low-temperature chlorination to produce titanium tetrachloride," using high-titanium blast furnace slag with vanadium-titanium coexistence as raw material to produce titanium tetrachloride. Due to the poor selectivity of the vanadium and titanium chlorination reaction during the chlorination process, the crude titanium tetrachloride produced by chlorination contains 0.80%–2.5% vanadium oxychloride impurities, which is more than four times that of crude TiCl4 produced by chlorinating conventional titanium raw materials.

[0003] Currently, no vanadium removal process can meet the vanadium removal requirements of high-vanadium crude titanium tetrachloride, making it difficult to realize the high-value utilization of titanium resources in high-titanium blast furnace slag. Summary of the Invention

[0004] The purpose of this invention is to provide an apparatus and method for reducing the solid content of slurry in a low-temperature chlorination leaching system, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] An apparatus for reducing the solids content of slurry in a low-temperature chlorination leaching system, comprising: a chlorination furnace;

[0007] Low-temperature chlorination scrubbing tower;

[0008] The spray section is located at the flue gas outlet of the chlorination furnace.

[0009] As a further embodiment of the present invention: a spray pipe is provided inside the low-temperature chlorination scrubbing tower, and the spray head is located above and opposite to the side where the spray pipe extends.

[0010] As a further embodiment of the present invention, the organic reagent injection device is used to add organic reagent at a rate of 15-30 kg / h.

[0011] As a further aspect of the present invention, the organic reagent is a fatty acid.

[0012] As a further aspect of the present invention, the solid content of the supernatant separated by the solid-liquid separator is controlled to be less than 20 g / L.

[0013] As a further aspect of the present invention, it also includes a feedback adjustment system, which is used to adjust the water spray volume of the spray section according to the temperature at the flue gas outlet.

[0014] As a further embodiment of the present invention: the feedback regulation system includes a control component and a temperature measuring component disposed at the flue gas outlet; both the temperature measuring component and the delivery pump are electrically connected to the control component, and the control component is used to perform feedback regulation on the delivery pump based on the temperature signal transmitted by the temperature measuring component.

[0015] As a further embodiment of the present invention, the spraying part is a baffle-type nozzle or a cross-type nozzle.

[0016] To achieve the above objectives, the present invention provides another technical solution as follows:

[0017] A method for reducing the solids content of slurry in a low-temperature chlorination leaching system, characterized by comprising the following steps:

[0018] The titanium tetrachloride flue gas obtained from low-temperature chlorination enters the low-temperature chlorination scrubbing tower, and the flue gas entering the scrubbing tower is cooled by spraying with slurry after heat exchange in the scrubbing tank.

[0019] Turn on the organic reagent spraying device and spray fatty acids into the scrubbing tower at a rate of 15-30 kg / h to ensure that the fatty acids are fully mixed with titanium tetrachloride. After pretreatment, the content of vanadium trichloride can be reduced from 0.8% to below 0.25%.

[0020] Turn on the transfer pump to pump the slurry from the spray tank into the solid-liquid separation device. Return the resulting supernatant to the low-temperature chlorination furnace and adjust the furnace temperature to maintain it at 500-550℃. The concentrated phase is then fed into the slurry evaporator of the refining system for further processing.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: by setting up an organic reagent injection device, an organic reducing agent is introduced into the low-temperature chlorination rinsing tower. While the organic reducing agent reduces vanadium and iron in the rinsing slurry of titanium tetrachloride, the impurities vanadium and iron in titanium tetrachloride can be pre-reduced simultaneously. By setting up a solid-liquid separator, the problem of heat exchanger blockage is avoided. The present invention achieves long-term operation of the rinsing system, while reducing the pressure on the subsequent refining system to remove impurities. This is conducive to improving the continuity and stability of the entire chlorination process and reducing the production cost of boiling titanium dioxide raw materials. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of a device for reducing the solid content of slurry in a low-temperature chlorination leaching system according to an embodiment of the present invention.

[0023] In the diagram: 1-Chlorination furnace, 2-Flue gas outlet, 3-Spray tank, 4-Low temperature chlorination scrubbing tower, 5-Refining system, 10-Spray section, 20-Heat exchanger, 30-First conveying pipeline, 40-Transfer pump, 50-Temperature measuring component, 60-Organic reagent spraying device, 70-Solid-liquid separator, 80-Control component, 401-Spray pipe, 601-Spray head, 602-Second conveying pipeline. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Example 1

[0026] Please see Figure 1 The present invention provides a structural diagram of an apparatus for reducing the solid content of slurry in a low-temperature chlorination leaching system, comprising: a chlorination furnace 1, a spray tank 3, and a low-temperature chlorination leaching tower 4; a spray section 10 is provided at the flue gas outlet 2 of the chlorination furnace 1; the spray tank 3 is used to collect the spray water discharged from the low-temperature chlorination leaching tower 4; the spray tank 3 provides spray water to the heat exchanger 20 through a delivery pump 40; the output end of the heat exchanger 20 is connected to the input end of the spray section 10 through a first delivery pipe 30;

[0027] A solid-liquid separator 70 is also provided between the heat exchanger 20 and the transfer pump 40. The solid-liquid separator 70 is used to separate the spray water input by the transfer pump 40 into solid and liquid, and to provide the heat exchanger 20 with the supernatant after solid-liquid separation.

[0028] The low-temperature chlorination rinsing tower 4 is also equipped with an organic reagent injection device 60; by introducing an organic reducing agent into the low-temperature chlorination rinsing tower 4, the organic reducing agent can simultaneously reduce vanadium and iron in the titanium tetrachloride slurry while reducing vanadium and iron impurities in titanium tetrachloride.

[0029] It also includes a refining system 5, wherein the concentrated phase output end of the solid-liquid separator 70 is connected to the slurry evaporator of the refining system 5.

[0030] This invention, by setting up an organic reagent injection device 60, introduces an organic reducing agent into the low-temperature chlorination scrubbing tower 4. While the organic reducing agent reduces vanadium and iron in the titanium tetrachloride slurry, it can simultaneously pre-reduce impurities such as vanadium and iron in the titanium tetrachloride. By setting up a solid-liquid separator 70, the problem of heat exchanger blockage is avoided. This invention achieves long-term operation of the scrubbing system, while reducing the pressure on the subsequent refining system to remove impurities. This is beneficial to improving the continuity and stability of the entire chlorination process and reducing the production cost of boiling titanium dioxide raw materials.

[0031] In a preferred embodiment of the present invention, the organic reagent spraying device 60 includes a nozzle 601 and a second conveying pipe 602. The nozzle 601 is installed at one end of the second conveying pipe 602, and the other end of the second conveying pipe 602 is connected to a branch pipe of the outlet pipe of the organic reagent conveying pump in the refining system.

[0032] In a preferred embodiment of the present invention, a spray pipe 401 is provided inside the low-temperature chlorination scrubbing tower 4, and the nozzle 601 is located above and opposite to the side where the spray pipe 401 extends.

[0033] In a preferred embodiment of the present invention, the spray pipe 401 is used to spray titanium tetrachloride flue gas that has been treated by dust collection.

[0034] In a preferred embodiment of the present invention, the organic reagent injection device 60 adds 15-30 kg / h of organic reagent.

[0035] In a preferred embodiment of the present invention, the organic reagent is a fatty acid; the fatty acid is thoroughly mixed with titanium tetrachloride to generate solid impurities which are then mixed into the rinsing tank 3.

[0036] In a preferred embodiment of the present invention, the solid content of the supernatant separated by the solid-liquid separator 70 is controlled to be less than 20 g / L.

[0037] In a preferred embodiment of the present invention, the present invention further includes a feedback adjustment system, which is used to adjust the water spray volume of the spray section 10 according to the temperature at the flue gas outlet 2.

[0038] In a preferred embodiment of the present invention, the feedback regulation system includes a control component 80 and a temperature measuring component 50 disposed on the flue gas outlet 2; both the temperature measuring component 50 and the delivery pump 40 are electrically connected to the control component 80, and the control component 80 is used to perform feedback regulation on the delivery pump 40 based on the temperature signal transmitted by the temperature measuring component 50.

[0039] The control unit 80 is also configured to shut down the delivery pump 40 if the temperature detected by the temperature measuring unit 50 is below 200°C, to prevent the flue gas temperature from being too low and causing titanium tetrachloride to become liquid. The control unit 80 is also configured to control the flow rate of the carbon tetrachloride slurry based on the temperature detected by the temperature measuring unit 50.

[0040] The spraying section 10 can be a baffle-type nozzle or a cross-shaped nozzle, which has good spraying function and can completely spray the titanium tetrachloride slurry, allowing the titanium tetrachloride slurry to fully contact the flue gas. The baffle-type nozzle includes a baffle installed at the fluid outlet, which causes the fluid to splash. The cross-shaped nozzle includes a cross-shaped support with multiple spray nozzles. The number of spraying sections 10 can be multiple, for example, 1 to 3 spraying sections 10 can be provided.

[0041] Example 2

[0042] Embodiment 2 of the present invention also provides a method for reducing the solid content of slurry in a low-temperature chlorination leaching system, comprising:

[0043] The titanium tetrachloride flue gas obtained from low-temperature chlorination enters the low-temperature chlorination scrubbing tower 4, and the flue gas entering the scrubbing tower is sprayed with slurry after heat exchange in the scrubbing tank 3 to cool it down.

[0044] Turn on the organic reagent spraying device 60 and spray fatty acids into the scrubbing tower at a rate of 15-30 kg / h to ensure that the fatty acids are fully mixed with titanium tetrachloride.

[0045] Turn on the transfer pump 40 to pump the mud from the spray tank 3 into the solid-liquid separation device 70. Return the obtained supernatant to the low-temperature chlorination furnace 1 and adjust the furnace temperature to maintain it at 500-550℃. The concentrated phase is then fed into the slurry evaporator of the refining system 5 for processing.

[0046] The titanium tetrachloride flue gas produced by the low-temperature chlorination process of this invention enters the low-temperature chlorination scrubbing tower 4 after dust collection. The temperature of titanium tetrachloride is cooled to about 120°C by spray condensation. During this process, the newly added organic reagent injection device 60 is turned on to add 15-30 kg / h of fatty acids. The fatty acids are fully mixed with titanium tetrachloride to generate solid impurities that are mixed into the scrubbing tank 3. Combined with the scrubbing residue and the uncollected tailings, titanium tetrachloride slurry is formed. The titanium tetrachloride slurry is pumped into the solid-liquid separator 70 by a submersible pump. The obtained supernatant is returned to the chlorination furnace 1 for temperature control. The concentrated phase is fed into the slurry evaporator of the refining system 5 for treatment.

[0047] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0048] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0049] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0050] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. An apparatus for reducing the solids content of slurry in a low-temperature chlorination leaching system, characterized in that, include: Chlorination furnace (1); The low-temperature chlorination scrubbing tower (4) has a spray section (10) installed at the flue gas outlet (2) of the chlorination furnace (1). An organic reagent spraying device (60) is installed inside the low-temperature chlorination scrubbing tower (4), and the organic reagent is fatty acid; Spray tank (3); used to collect titanium tetrachloride leached from the low-temperature chlorination leaching tower (4); the spray tank (3) provides spray liquid to the heat exchanger (20) through the transfer pump (40); the output end of the heat exchanger (20) is connected to the input end of the spray section (10) through the first transfer pipe (30); A solid-liquid separator (70) is also provided between the heat exchanger (20) and the transfer pump (40). The solid-liquid separator (70) is used to perform solid-liquid separation on the titanium tetrachloride slurry input by the transfer pump (40) and to provide the heat exchanger (20) with the supernatant after solid-liquid separation. It also includes a refining system (5), the concentrated phase output end of the solid-liquid separator (70) is connected to the slurry evaporator of the refining system (5); the organic reagent spraying device (60) includes a nozzle (601) and a second conveying pipe (602); the nozzle (601) is installed at one end of the second conveying pipe (602), and the other end of the second conveying pipe (602) is connected to the branch pipe of the organic reagent conveying pump outlet of the refining system (5).

2. The apparatus for reducing the solid content of slurry in a low-temperature chlorination leaching system according to claim 1, characterized in that, The low-temperature chlorination scrubbing tower (4) is equipped with a spray pipe (401).

3. The apparatus for reducing the solid content of slurry in a low-temperature chlorination leaching system according to claim 2 is characterized in that, The nozzle (601) is positioned above and opposite to the side where the spray pipe (401) extends.

4. The apparatus for reducing the solid content of slurry in a low-temperature chlorination leaching system according to claim 1, characterized in that, The organic reagent injection device (60) adds 15-30 kg / h of organic reagent.

5. The apparatus for reducing the solid content of slurry in a low-temperature chlorination leaching system according to claim 1, characterized in that, The solid content of the supernatant separated by the solid-liquid separator (70) is controlled to be within 20 g / L.

6. A method for reducing the solids content of slurry in a low-temperature chlorination leaching system using the apparatus according to any one of claims 1-5, characterized in that, Includes the following steps: The titanium tetrachloride flue gas obtained by low-temperature chlorination enters the low-temperature chlorination scrubbing tower (4), and the flue gas entering the low-temperature chlorination scrubbing tower (4) is sprayed with slurry after heat exchange in the spray tank (3) to cool it down. Turn on the organic reagent spraying device (60) and spray fatty acids into the low-temperature chlorination scrubbing tower (4) at an addition rate of 15-30 kg / h, so that the fatty acids and titanium tetrachloride are fully mixed. Turn on the delivery pump (40) to pump the mud from the spray tank (3) into the solid-liquid separator (70), return the resulting supernatant to the low-temperature chlorination furnace (1) and adjust the furnace temperature to maintain at 500-550℃. The concentrated phase is then pumped into the slurry evaporator of the refining system (5) for treatment.

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